1. Field of the Invention
The present invention generally relates to a bicycle hub outer. More particularly, the present invention relate to a bicycle hub outer configured to be mounted in a freely rotatable manner to the hub shaft of a bicycle hub. The present invention also relates to a bicycle hub provided with such a bicycle hub outer.
2. Background Information
A bicycle is generally provided with a frame that constitutes the body framework of the bicycle and a rear hub for a rear wheel is generally connected to a rear end portion of the frame. The rear hub normally comprises a hub shaft arranged at the rotational center of the rear wheel, an outer and a hub shell mounted such that they rotate freely about the hub shaft, and a one-way clutch configured to connect the outer and the hub shell in such a manner that they can rotate relative to each other in only one direction. The hub shell is a cylindrical member to a radially outer portion of which the spokes of the rear wheel are connected. The outer is a cylindrical member arranged closely adjacent to the hub shell in the axial direction and engaged with an inner radially facing portion of a sprocket.
With such a bicycle, when the rider turns the pedals, the chain rotates the sprocket and the outer rotates integrally with the sprocket. Meanwhile, the one-way clutch causes the hub shell to rotate integrally with the outer main body and, as a result, the rear wheel rotates.
There have been proposals for an outer of this type that is designed for use with a multiple-sprocket cassette provided with a plurality of sprockets of different diameters so that a variety of speeds can be obtained by following a prescribed speed changing procedure. For example, a bicycle hub of this type is disclosed in Japanese Laid-Open Patent Publication No. 8-175459. The plurality of sprockets are arranged along the axial direction and each have an engaging section formed on an inner radially facing portion thereof, the engaging section comprising depressions and protrusions formed in a repeated manner along the circumferential direction. Meanwhile, the radially outward facing surface of the outer includes a rotation preventing section having a splines that run in the axial direction and are configured such that they can engage with the engaging sections of the sprockets.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved bicycle hub. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.